The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 03, 1990
Filed:
Dec. 29, 1988
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A leuco dye of the formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 each represent a lower alkyl group; A represents ##STR2## in which R.sup.9 and R.sup.10 each represent hydrogen, provided that both R.sup.9 and R.sup.10 may not be hydrogen, --CN or --COR.sup.14 in which R.sup.14 represents a phenyl group which is unsubstituted or is substituted by an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, or a halogen, a naphthyl group which is unsubstituted or is substituted by an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms or a halogen, or a lower alkoxyl group, ##STR3## in which ##STR4## represents a phenyl group or a naphthyl group, R.sup.11 represents hydrogen, a lower alkyl group, a halogen, an amino group, which is unsubstituted or is substituted by an alkyl group having 1 to 4 carbon atoms, or a nitro group, or ##STR5## in which R.sup.12 represents a lower alkyl group, or ##STR6## in which R.sup.13 represents hydrogen, a lower alkyl group, a halogen, a hydroxyl group, a trifluoromethyl group, a nitro group, an amino group which is unsubstituted or is substituted by an alkyl group having 1 to 4 carbon atoms, or amide group. These dyes absorb in the near-infrared region and yields colored images with a color developer therefor with excellent preservability.